Extension-ladder.



Ng. 690,204. Patented nec. si, 190|.

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EXTENSION LADDER'.

(Application filed June 18, 1901.]

(No Model.)

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UNITED STATES APATENT OFFICE.

CHARLES H. STRAUSS AND FRANK JOHNSON, OF SEATTLE, VASHINGTON.

EXTENSION-LADDER.

SPECIFICATION forming part of Letters Patent No. 690,204, dated December 31, 1901, Application iiled June 18, 1901. Serial No. 64,985. (No model.) I

To a/ZZ whom, t nea/g concern.-

Beit known that we, CHARLES H. STRAUSS and FRANK JOHNSON, citizens of the United States, residing at Seattle, in the county of King and State of Washington, have invented certain new and useful Improvements in Extension-Ladders; and we do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in extension-ladders, consisting of a series of sections movable one upon the other and embodying operating mechanism whereby said sections may be elevated or extended to increase the length of the ladder and to be lowered or folded to decrease the height of the ladder to approximately thelength of the basesection; and the object of the invention is to provide a sectional extensible ladder which is comparatively simple of construction, efficient in operation, and in which power mechanism is provided by means of which the ladder-sections may be readily and conveniently extended and collapsed.

The invention provides a ladder which is adapted for use bycarpenters, painters, plasterers, and other mechanics and by fire brigadesin reaching elevated points in a building and which also is susceptible of use as a reescape, which may form a permanent fixture capable of being elevated to the desired height whenever it is desired to employ it.

The invention isillustrated in the accompanying drawings, in which- Figure lis a front elevation of an extensionladder embodying our invention, showing the ladder-sections extended or elevated. Fig. 2 is a vertical longitudinal section of the same. Fig. 3 is a view similar to Fig. 2, showing the ladder-sections collapsed, and Fig. et is a cross` section of the ladder in a closed position.

Referring to the drawings, the numerals 1, 2, and 3 represent the parts or sections of an extensible ladder, each of which is provided with side rails 5, having inclined strips 6 attached thereto to form an outer continuous longitudinal tongue to enter a continuous longitudinal` angular channel to receive a corresponding tongue on the other section. The

section 2, for instance, is provided with the side rail and a continuous longitudinal inclined side strip 6, the outer edge of the side strip forming a continuous longitudinal tongue 7, sliding ina continuous longitudinal angular channel S on the corresponding side of the base-section 1, and said rail and side strip acting in conjunction to provide a continuous longitudinal angular channel S', similar to the guideway 8 upon the base-section 1 and receiving the continuous longitudinal tongue 7 upon the connecting side of the ladder-section 3. with continuous inclined side rails 5, which slide in the continuous longitudinal angular channels of lhe sectionhelow the same. The ladder-sections l, 2, 3, and 4 are of correspondingly-decreasing widths, so as to slide one Within the other in the usual manner.' To the rungs 9 of the sections 1, 2, and 3 are se- The top section 4 is provided Y cured pairs of spaced longitudinal bars 10,

which serve as guides for chains, cables, or ropes, hereinafter described, and as supports for a series of rods or vshafts 11, mounted upon the upper end of the base-section 1 and at the upper and lower ends of the two intermediate sections 2 and 3, said rods or shafts carrying friction wheels or rollers 12.

To the top portions of the side rails 5, below the upper section, I provide braces la, so that when the sections are run upward the braces coact with the bottom rungs of the sections above the base-sections. y By this means arigid connection is formed between each section of the ladder. v,

Upon the base-section is mounted a winding-shaft 13, provided at one end with acrankhandle 14, and said section is also provided with a recess l5, adapted to receive a pin 16, inserted therein to lie in the path of movement of the crank-handle, so as to lprevent retrograde rotation of the shaft when the ladder-sections have been adjusted to the desired height. To this shaft is connected one end of a rope, cable, or chain 17, which passes upwardly between the longitudinal spaced bars on the ladder-sections and over the friction-rollers ]2 at the upper end of the basesection 1, thence Linder and around the friction-roller at the lowerend ofsection 2, thence around the friction-roller at the upper end of said section 2 and upon the lower end of section 3, and finally around the friction-roller IOC) at the upper end of section 3 and is connected to the ladder-section 4. One end of a tailrope 18 is also connected to the ladder-section 4, and its opposite end is connected to the crank-shaft, so as to Wind thereupon in a re verse direction tothe chain, cable, or rope 17, so that when said crank-shaft is operated one rope, chain, or cable will'pay out while the other is being wound up, whereby when the ladder-sections are being extended or elevated the rope 17 will be wound upon the shaft and the tail-rope simultaneously unwound therefrom to allow the section to be extended, and, vice versa, when the shaft is turned in the opposite direction toclose up the sections. The tail-rope may, however, be left free at its lower end, so that it may be grasped and pulled upon to draw down the section in case either one of the sections should hang while the ladder is being collapsed.

In operation it will be readily understood that when it is desired to extend the ladder the crank-shaft is turned in the proper direction to Wind up the draft-rope and unwind the tail-rope, whereby the ladder-sections will be elevated, and as soon as one comes to a stop the other will continue to move upward until the ladder is extended to its fullest extent, when the stop-pin is inserted within its opening to arrest the motion ot' the crankshaft. When the crank-shaft is turned in the reverse direction, the tail-rope will be wound and-tho draft-rope unwound, so as to draw upon the ladder-sections to cause them to move smoothly and evenly together to close or collapse the ladder.

From the foregoing description, taken in connection with the accompanying drawings, the construction, inode ot' operation, and advantages of the in-vention will be readily understood, and it will be seen that the invention provides an extensible ladder which is comparatively simple of construction, cornpact, and in which the parts are adapted to operate in an effective manner.

Changes in the form, proportion, and minor details of construction may be made within the scope of the 1invention without departing from the spirit or sacrificing any of the advantages thereof.

Having thus fully described our invention, what we claim as new, and desire to secure by Letters Patent, is-

The herein-described extension-ladder consisting of sections of equal lengths, each section below the top section having side rails with continuous longitudinal inclined outer face portions and inner continuous iongitudnal angular channels, and each of the sections decreasing in width so as to permit of the inclined side rails of each section to slide Vone within the other in said channels, the top section having inclined side rails to engage and slide within the channels of the section below the same, and means connected to said sections whereby to raise the same in an extended position or to fold or slide the sections one within the other, substantially as specified.

In testimony whereof we have hereunto set our hands in presence of two subscribing witnesses.

CHARLES STRAUSS. FRANK JOHNSON.

Witnesses:

A. H. JAooBsEN, LoUIs DoFsEN. 

